1. Field of the Invention
The present invention relates to a plate for a rocker joint chain, wherein the plate includes two longitudinal legs and two vertical legs that together enclose a plate recess.
2. Description of the Related Art
A known rocker joint chain is disclosed in published German patent application DE 103 16 441 A1. That chain has sequentially arranged plates in a plurality of adjacent rows perpendicular to the direction of chain travel, and the plates in adjacent rows partially overlap and are connected by rocker members that extend into the plates in the direction perpendicular to the direction of chain travel. Two pairs of rocker members extend through a recess in each plate, and the outermost rocker members that face away from each other abut the front and rear inside surfaces of the plate recess. The innermost rocker members that face each other abut the front and rear inside surfaces of the recesses of adjacent plates. The facing surfaces of the rocker members of a rocker member pair roll against each other when the rocker joint chain transitions from a straight, extended form to a curved form. Such rocker joint chains are used in a variable speed drive unit of a belt-driven conical-pulley transmission, a so-called continuously variable transmission (CVT), for example.
The plates include tabs that are used to help assemble the rocker joint chain, and the tabs contact a guide rail of the CVT transmission in the event of strand vibration. Such guide rails are provided to limit the transverse vibrations of the rocker joint chain. As the torque increases, the strand vibrations increase in the CVT transmission. As a result, the tabs cause pitting in the guide rail when the transverse vibrations are high.
Guide rail wear also reduces the useful life of the rocker joint chain. An object of the present invention is therefore to provide plates that cause less wear of the chain guide rail in comparison with prior art plates.